#!/usr/bin/env bash
#
# OpenCoarrays version @CAF_VERSION@
#
# Coarray Fortran (CAF) Compiler Wrapper
#
# Invokes the chosen Fortran compiler with the received command-line
# arguments.
#
# Copyright (c) 2015-2022, Sourcery Institute
# Copyright (c) 2015-2022, Archaeologic Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of the Sourcery, Inc., nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL SOURCERY, INC., BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

# Exit on error. Append "|| true" if you expect an error.
set -o errexit
# Exit on error inside any functions or subshells.
set -o errtrace
# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
set -o nounset
# Catch the error in case mysqldump fails (but gzip succeeds) in `mysqldump |gzip`
set -o pipefail
# Turn on traces, useful while debugging but commented out by default
# set -o xtrace

#---------------------------
# Begin configured variables
#---------------------------
# List of variables needing configuration:
#
# CAF_VERSION, opencoarrays_aware_compiler, Fortran_COMPILER, CAF_MODDIR,
# CAF_MPI_Fortran_LINK_FLAGS, CAF_MPI_Fortran_COMPILE_FLAGS,
# CAF_LIBS, THREADS_LIB, CAF_MPI_LIBS
#

caf_version='@CAF_VERSION@' # fetched from `git describe` and/or
# `.VERSION` file
oca_compiler="@opencoarrays_aware_compiler@" # True for GFortran > 5.0.0

# Compiler used to build OpenCoarrays; runtime must match compiler used during build
cafc="@Fortran_COMPILER@"
if [[ "${cafc}" == @*@ || -z "${cafc}" ]]; then
  cafc=gfortran
fi
caf_mod_dir="@CAF_MODDIR@"    # location of extensions module, needed for non-OCA compilers
mod_dir_flag="-I"


# Ideally these should be absolute paths. Since they are array
# variables multiple libs (absolute or not) can be specified provided
# proper quoting is used, when @var@ is expanded. (i.e., expands with
# double quotes around each library w/path to ensure proper word
# splittling for paths with spaces) Handling of paths is complex
# between CMake and pkg-config: pkg-config (new enough versions) will
# theoretically expand paths with spaces escaped or the path
# quoted. CMake handles spaces in paths natively, but also sort of
# punts by making ; a field separator... So long story short,
# pkg-config output *should* __ALREADY__ handle word splitting, and
# variables expanded from CMake should be appropriately quoted.

# shellcheck disable=SC2054
mpi_link_flags=(@CAF_MPI_Fortran_LINK_FLAGS@) # e.g. `pkg-config
# --libs-only-other mpich`
# __*AND*__ `pkg-config
# --libs-only-L`
mpi_compile_flags=(@CAF_MPI_Fortran_COMPILE_FLAGS@)
caf_libs=(@CAF_LIBS@) # e.g. "libcaf_mpi" "libcaf_extensions",
threads_lib=@THREADS_LIB@ # pthreads or compatible, needed for windows
# preferably full paths, but could be
# combination of -L... and -lcaf_mpi...
mpi_libs=(@CAF_MPI_LIBS@) # e.g. `pkg-config --libs-only-l` or full paths
# to MPI libs

#-------------------------
# End configured variables
#-------------------------

if [[ "${BASH_SOURCE[0]}" != "${0}" ]]; then
  __i_am_main_script="0" # false

  # shellcheck disable=SC2154
  if [[ "${__usage+x}" ]]; then
    if [[ "${BASH_SOURCE[1]}" == "${0}" ]]; then
      __i_am_main_script="1" # true
    fi
    __caf_tmp_source_idx=1
  fi
else
  # shellcheck disable=SC2034
  __i_am_main_script="1" # true
fi

# Set magic variables for current file, directory, os, etc.
__dir="$(cd "$(dirname "${BASH_SOURCE[${__caf_tmp_source_idx:-0}]}")" && pwd)"
__file="${__dir}/$(basename "${BASH_SOURCE[${__caf_tmp_source_idx:-0}]}")"
# shellcheck disable=SC2034
__base="$(basename "${__file}")"
cmd="${__base}"

# Set installation prefix. Compute this dynamically assuming this script is in a bin/ subdir
# Dereference symbolic links and canonicalize (i.e., abs path) prefix in case stow, homebrew, etc being used
# mac OS doesn't have readlink -f, so need to crawl symlinks manually.
# See: https://stackoverflow.com/questions/1055671/how-can-i-get-the-behavior-of-gnus-readlink-f-on-a-mac
current_dir="${PWD}"
cd "${__dir}" || exit 5
  target_file="${__file}"
  max_iter=1000
  iter=0
  while [[ -L "${target_file}" ]]; do
    target_file="$(readlink "${target_file}")"
    cd "$(dirname "${target_file}")" || exit 5
    target_file="$(basename "${target_file}")"
    if ((++iter >= max_iter)); then
      echo "Failed to compute OpenCoarrays instalation prefix!" >&2
      echo "Likely cause: circular symlink cycles." >&2
      echo "Aborting!" >&2
      exit 200
    fi
  done
  true_dir="$(pwd -P)"
  true_dir="${true_dir%/}"
  # shellcheck disable=SC2034
  prefix="${true_dir%/bin}"
  # echo "Install prefix is ${prefix}" # for debugging
cd "${current_dir}" || exit 5
# echo "Current directory is $(pwd)"
# echo "This script is in ${__dir}"

# Error tracing
# requires `set -o errtrace`
__caf_err_report() {
  local error_code
  error_code=${?}
  echo "Error in ${__file} in function ${1} on line ${2}. Please report this error at http://bit.ly/OpenCoarrays-new-issue" >&2
  exit ${error_code}
}
# Always provide an error backtrace
trap '__caf_err_report "${FUNCNAME:-.}" ${LINENO}' ERR

# See if we are compiling or compiling and/or linking
__only_compiling () {
    for arg in "${@}"; do
      if [[ "${arg}" == "-c" ]]; then
        return 0
      fi
    done
    return 1
}

#--------------------------------------------------------------------------
# End configured variables, now process them and build compile/link command
#--------------------------------------------------------------------------


substitute_lib () {
  # Try to substitute a shared or static library if requested library is missing
  # Some package managers only install dynamic or static libs
  if ! [[ -f "${1}" && "${1}" = *.* ]] ; then
      case "${1##*.}" in
          a|lib)
              for suff in so dylib dll ; do
                  if [[ -f "${1%.*}.${suff}" ]] ; then
                      echo "${1%.*}.${suff}"
                      return
                  fi
              done
              # If we get here, original lib DNE, and no alternates found
              echo "Failed to find static library ${1} or shared library alternatives." >&2
              exit 1
          ;;
          so|dylib|dll)
              for suff in a lib ; do
                  if [[ -f "${1%.*}.${suff}" ]] ; then
                      echo "${1%.*}.${suff}"
                      return
                  fi
              done
              # If we get here, original lib DNE, and no alternates found
              echo "Failed to find shared library ${1} or static library alternatives." >&2
              exit 1
          ;;
      esac
  else
    echo "${1}"
  fi
}

# Always make extensions module available, user can choose whether to `use` it or not
caf_pre_flags=("${mod_dir_flag}${prefix%/}/${caf_mod_dir}")

if [[ "${oca_compiler}" == true ]]; then
  if [[ -z "${caf_pre_flags[*]:-}" ]]; then
    caf_pre_flags=('-fcoarray=lib')
  else
    caf_pre_flags+=('-fcoarray=lib')
  fi
fi
if [[ -n "${mpi_compile_flags[*]:-}" ]]; then
  for compileflag in "${mpi_compile_flags[@]:-}"; do
      caf_pre_flags+=("${compileflag}")
  done
fi
if [[ -n "${mpi_link_flags[*]:-}" ]]; then
  if ! __only_compiling "${@}"; then
    for linkflag in "${mpi_link_flags[@]:-}"; do
      caf_pre_flags+=("${linkflag}")
    done
  fi
fi

# Now do libraries, IN CORRECT ORDER, to append to command
if [[ -n "${caf_libs[*]:-}" ]]; then
  for lib in "${caf_libs[@]:-}"; do
    caf_added_libs+=("$(substitute_lib "${prefix%/}/${lib}")")
  done
fi

if [[ -n "${threads_lib}" ]]; then
  caf_added_libs+=("${threads_lib}")
fi

if [[ -n "${mpi_libs[*]:-}" ]]; then
  for lib in "${mpi_libs[@]:-}"; do
    caf_added_libs+=("$(substitute_lib "${lib}")")
  done
fi

usage() {
  echo ""
  echo " ${cmd} - Fortran compiler wrapper for OpenCoarrays"
  echo ""
  echo " Usage: ${cmd} <fortran-source-file> [compiler-options] [object-files] [linker-options]"
  echo ""
  echo " Wrapper options:"
  echo "   --help, -h               Show this help message and exit"
  echo "   --version, -v, -V        Report version and copyright information and exit"
  echo "   --wrapping, -w, --wraps  Report the name of the wrapped compiler and exit"
  echo "   --show, -s, -show        Show how this wrapper will call the compiler and exit (dry run)"
  echo ""
  echo " Example usage:"
  echo ""
  echo "   ${cmd} foo.f90 -o foo"
  echo "   ${cmd} -v"
  echo "   ${cmd} --help"
  echo "   ${cmd} -s"
  echo ""
  echo "OpenCoarrays ${caf_version} ${cmd} supports three categories of compilers"
  echo "with the following restrictions for each use case:"
  echo ""
  echo " 1. With an OpenCoarrays-Aware (OCA) compiler (GNU 5.1.0 or later),"
  echo "   a. If any of the options listed above appear, any remaining arguments are ignored."
  echo "   b. If present, any Fortran <source-file(s)> must have a name of the form:"
  echo "      *.f90, *.F90, *.f, or *.F. "
  echo ""
  echo " 2. With non-OCA CAF compilers (Intel or Cray),"
  echo "   a. Observe restrictions 1a-d above."
  echo "   b. Access OpenCoarrays collective subroutines via use association with an only clause,"
  echo "      e.g., 'use opencoarrays, only : co_sum,co_broadcast' "
  echo ""
  echo " 3. With non-CAF compilers (all compilers not named above),"
  echo "   a. Observe restrictions 1a-d above."
  echo "   b. Access OpenCoarrays capabilities via use association ('use opencoarrays')."
  echo "   c. The only CAF statements or expressions allowed are the following:"
  echo "      * 'num_images()' "
  echo "      * 'this_image()' with or without arguments"
  echo "      * 'sync all' with or without arguments."
  echo "      * 'sync images' with or without arguments."
  echo "      * 'error stop' without arguments."
  echo "      * 'co_sum', 'co_broadcast', 'co_max', 'co_min', or 'co_reduce'"
  echo ""
  echo " The caf wrapper will append -L..., -l..., and other required flags as necessary"
  echo " to link against OpenCoarrays, using values that get set during the OpenCoarrays"
  echo " build and installation."
  echo ""
}

# Print useage information if caf is invoked without arguments
if ((${#} == 0)); then
  usage | ${PAGER:-less -i -F -X -M -J}
  exit 1
fi

if [[ ${1} == -[vV] || ${1} == '--version' ]]; then
  echo ""
  echo "OpenCoarrays Coarray Fortran Compiler Wrapper (caf version ${caf_version})"
  echo "Copyright (C) 2015-2022 Sourcery Institute"
  echo "Copyright (C) 2015-2022 Archaeologic Inc."
  echo ""
  echo "OpenCoarrays comes with NO WARRANTY, to the extent permitted by law."
  echo "You may redistribute copies of OpenCoarrays under the terms of the"
  echo "BSD 3-Clause License.  For more information about these matters, see"
  echo "the file named LICENSE that is distributed with OpenCoarrays."
  echo ""
  exit 0
elif [[ ${1} == '-w' || ${1} == '--wraps' || ${1} == '--wrapping' ]]; then
  echo "${cmd} wraps ${cafc}"
  exit 0
elif [[ ${1} == '-s' || ${1} == '--show' || ${1} == '-show' ]]; then
  if (($# > 1)); then
    args="${*:2:$((${#} - 1))}"
  else
    args="\${@}"
  fi
  if [[ "${caf_pre_flags[*]:-}" ]]; then
    compiler_args=("${caf_pre_flags[@]}")
  fi
  if [[ "${args}" ]]; then
    compiler_args+=("${args}")
  fi
  if [[ "${caf_added_libs[*]:-}" ]]; then
    if ! __only_compiling "${@}"; then
      compiler_args+=("${caf_added_libs[@]}")
    fi
  fi
  echo "${cafc}" "${compiler_args[@]}"
  exit 0
elif [[ ${1} == '-h' || ${1} == '--help' ]]; then
  # Print usage information
  usage | ${PAGER:-less -i -F -X -M -J}
  exit 0
elif [[ "${oca_compiler:-}" != "true" ]]; then
  # Transform file(s) with the .f90, .F90, .f, or .F extension, if present:
  # Loop over all arguments and perform simple search & replace source transformation on any Fortran sources
  i=0
  for arg in "${@}"; do
    src_extension="${arg##*.}"
    ((i+=1)) # Increment i to keep track of which arg we're processing
    if [[ "${src_extension}" == [fF]90 || "${src_extension}" == [fF] ]]; then
      # Edit & copy the source to replace CAF syntax with calls to public procedures in opencoarrays.f90:
      sed -e 's/sync all/call sync_all/g' -e 's/error stop/call error_stop/g' \
        -e 's/sync images/call sync_images/g' "${arg}" >"caf-${arg}"
      # Replace the file name in command-line argment $i with the new name before invoking the compiler:
      set -- "${@:1:$((i - 1))}" "caf-${arg}" "${@:$((i + 1)):$((${#} - i))}"
    fi
  done
fi

# Invoke the compiler along with all command-line arguments:
if [[ "${caf_pre_flags[*]:-}" ]]; then
  compiler_args=("${caf_pre_flags[@]}")
fi
if [[ "${*:-}" ]]; then
  compiler_args+=("${@}")
fi
if [[ "${caf_added_libs[*]:-}" ]]; then
  if ! __only_compiling "${@}" ; then
    compiler_args+=("${caf_added_libs[@]}")
  fi
fi
#set -o xtrace # Show what we're doing
set +o errtrace
set +o errexit
if "${cafc}" "${compiler_args[@]}" ; then
  exit $?
else
  return_code=$?
  echo "Error: command:" >&2
  echo "   \`${cafc} ${compiler_args[*]}\`" >&2
  echo "failed to compile." >&2
  exit "${return_code}"
fi
